The cardiovascular system is an integrated system when the performance of each part depends on the characteristics of all the other parts and the topologic relationships among them. If students are to understand whole-system behaviors, the function of the system must be taught as a whole. Our previous work has developed simulations that are successfully used for teaching the normal physiology of the: action potential, isolated muscle, isolated heart. systemic circulation, heart-lung blood pump and closed circulatory loop. The first four are Currently published for teaching first year medical students normal cardiovascular physiology. Cardiovascular pathophysiology is an important medical topic, as well as a useful tool for reinforcing knowledge about normal physiology. For example, valvular diseases (e.g., regurgitation or stenosis) illustrate by counter-example the role of properly functioning heart valves. We propose to develop the following new pathophysiology models: Coronary Heart Disease; Cardiomyopathies; Valvular Heart Disease; Arteriosclerosis; Hypertension; Peripheral Vascular Disease; Normal Fetal/Neonatal Circulation, Congenital Circulatory Diseases; and Arrhythmias. For each topic, two kinds of computer software will be developed: 1) a numerical simulation that predicts instantaneous pressures, flows, volumes and oxygen concentrations; and 2) qualitative models that serve as knowledge-bases for student diagnostic problem solving with the Diagnostic Critical software.